the only customization is CellStyle using a
static resource style that is a TextBox and a Binding of the TextBlock.Text to
RelativeSource Mode="TemplatedParent" using a custom converter to extract data from my objects

other important thing is that the objects contains one object and a string; the problem happens on the object when I set a style on its column

Maybe that the system used by me to accomplish the styling was not the minimal right way (please check code below) or maybe that I have some mistake in my code; please feel free to let me know if there is a similar but more correct way to do the thing.

The code: ( when you see the bug try to set ShowBug var to false to show the correct behavior but unstyled )